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Copy 4Kb in Assembly?Here's an interesting problem: what's the best way to copy a block of 4Kb in assembly? The most obvious solution is to use [B]LDIR[/B]: [CODE] l…
Converting an integer arbitrary large binary number into a printable decimal formThis was asked a long ago at the comp.sys.sinclair newsgroup. At that time, I came up with a solution by extrapolating the classic algorithm of suces…
...
cp low(NUMERO)
jr nz,BucAdd
ret
endp ...
cp low(NUMERO)
jr nz,BucPrint2Dig
ret
endp ...A "generic" loader for +3(e)I've made this loader for 128k games in +3DOS. [CODE]dos_open equ 262 dos_close equ 265 dos_abandon equ 268 dos_read equ 274 dos_write equ 277 dos_s…
... end of the list?
jr nz,cerrar ; it is, going to ... points to next block
jr bucle ; closing the loop
Math Quiz - MultiplicationThe topic is fast multiplication routines, from 8x8 to 32x32 and all points in between. These functions sit underneath floating point libraries, gen…
... />
sla h
jr c, loop_12
sla ... />
sla h
jr c, loop_16
... br /> rla
jr nc, loop_12
... e
dec e
jr nz, no_swap
ex ...Ghosts n' Goblins loaderI'm trying to put Ghosts n' Goblins onto a +3 disk but struggling to understand the mc loader. Basic loader [code] ink 7 : clear 25000 : load "" cod…
... 65075: OR L
65076: JR NZ, 65071
65078: CALL 65188 ... AF'
65125: JR NZ, 65140
65127: JR NC, 65150
65129 ... AF'
65368: JR NZ, 65385
65370: JR NC, 65395
... /> 65449: DEC A
65450: JR NZ, 65449
65452: ...Unusual custom turbo loaders - with sourcesI have always been fascinated by turbo loaders; my games all feature a TZX version with one of such schemes implemented, and I have been experimentin…
... br /> OR L
JR NZ,65380
CALL 65481
OR E
JR NZ,65433
RET
...
OR L
JR NZ, 65380
CALL 65481
INC H
JR NZ, 65392
LD B, 201 ... D
OR E
JR NZ, 65433
RET
...Currah ?Speech channelIt seems to me that it would be nice to be able to send words to the ?Speech with PRINT #5;"Speak English to me, Jimmy" or some such. There really i…
... /> or l ; zero
jr nz, speak_2 ; jump if not
cp ' ' ; space?
jr z, say_it ; jump to say ... cp 13 ; carriage return
jr z, say_it ; jump to say ... ), a ; done
jr done
allophones:
Help with Manic Miner tweaksPlease. :) This is the Software Projects version, simply as I had it to hand. [B]Problem 1:[/B] I've learned a bit (actually quite a bit) and manag…
... DEC C ; 37104 13
JR NZ, L_90E2 ; 37105 32 239
JR NZ, L_9109 ; 37115 32 12
JR NZ, L_8FEA ; 36823 32 17
JR NZ, L_8FEA ; 36829 32 11
Problem Reading the KeyboardHi Folks, I'm working my way through Toni Baker's rather good book and thought I'd write some code to scan the keyboard and store the results so tha…
... key in segment
JR NZ,_storeKey2 ;If the bit ... key in segment
JR NZ,_storeKey3 ;If the bit is ... key in segment
JR NZ,_storeKey4 ;If the bit ... key in segment
JR NZ,_storeKey5 ;If the bit is ...Machine Code in 30 minutes - car gameWotcha folks, 30 years on and I'm still struggling with Machine Code. I'm going through the 30-minute tutorial on the Chuntey blog and it's all made…
... ,(c)
cp 191
jr nz, moveright
inc l
cp 191
jr nz, dontmove
dec l
JR NZ MOVERIGHT? This really infuriates me ...Kempston joystick detectionIn both [url="http://skoolkit.ca/disassemblies/manic_miner/asm/34252.html#34332"]Manic Miner[/url] and [url="http://skoolkit.ca/disassemblies/jet_set…
ROM Calculator TrigHello, These Christmas holidays I finally have time to devote myself a little to the speccy . I have a question about how the ROM calculator implem…
... be the counter for dec-jr-nz
CALL GEN_ENT_1 ;In effect ... be the counter for dec-jr-nz
CALL GEN_ENT_1 ;In effect ... FP_ADDITION
DEFB FP_DEC_JR_NZ ;dec-jr-nz
DEFB SINELOOP - $ ;;to ...ZERO Emulator - BugsI have been using Zero emulator to experiment a few routines in assembly, since it has a somewhat usable debugger. However I believe I found a few b…
I have been using Zero emulator to experiment a few routines in assembly, since it has a somewhat usable debugger.
However I believe I found a few bugs, some in "zero" application, and some on emulation itself.
The following example ...z80 assembly helpEver since I was a child I wanted to program my zx81 then my zx spectrum + 2. However, it was such a mystical beast and I only ever used BASIC not kn…
... top of screen yet?
jr nz,loop ; no, carry on.
jr nz,loop ???
ret - returns to ...Text scroller and custom fontYesterday I was testing this text scroll routine taken from Jonathan Cauldwell's Intro Maker (labels have been inserted to allow partial code relocab…
... 00654
INC E
JR NZ, L_35381
L_35387: HALT
INC E
RET NZ
CALL L_35414
JP ... DE)
AND C
JR Z,L_35464
INC (HL ... HL)
AND A
JR NZ,L_35485
LD HL, MESSAGE ...Must be missing the point - machine code... Hi Folks, Trying my hand at machine code again but falling at the first hurdle. I hand crafted the following to run at address 62000 and the co…
... H
DEC C
JR NZ, Loop2
LD H, & ... /> NOP
DEC B
JR NZ, Loop1
RET
[/code ...Fast way to clear the screen ?So I was wondering fastest way to clear the screen. I've tried this and this works but is it better than CLS ? LD HL,16384 LD BC, 6144 Loop…
Scrolling loader counter in 85 T-States?Would it be possible to write a scrolling loader counter in 85 T-States? I have a custom screen load routine that loads attribute first, then the …
... /> and 7
jr nz,loop1 ; jr if not 8 pixels
cp $5b
jr nz,loop2 ;
ret ... ; 07ts
jr nz, lddelay ; 07/12ts ; jr if not 8 pixel ... dlyloop: dec a ; 04ts
jr nz, dlyloop ; 07/12ts
; ...A sped up pixel-shift routine for 1-byte–wide spritesHere’s an optimized (for speed) real-time sprite shifting routine for sprites that are one byte wide. It uses no memory variables for storage of inte…
... a ;is it zero?
jr z,msl_skip_shift ;okay, no shifting ... will be 0 then
jr nz,msl_shift_done ;if not, we're ... it back in L
jr c,msl_shift_done ;if ADD A ...ZXSCLZF - Yet another Screen CompressorQuick disclaimer before I continue, this compressor does not shrink screens as small as some of the others posted here, in particular the very good z…
... ; 13t - into later code
jr _ulzfa020 ; 12t
;;
;; ... then need next byte
jr nz,_ulzfa030 ; 12/7t - 7 ... inc hl ; 6t - next
jr _ulzfa020 ; 12t - back to the ... *** loaded from above
ret nz ; 11t - if not equal to ...Flood Fill IssueHi Folks, Came across the following Flood Fill routine by John Metcalf: [code]; scanline fill by John Metcalf ; call with d=x-coord, e=y-coo…
... a 60020 B7
jr z,goright 60021 28 ... 98 EA
jr nz,seekleft 60029 20 F4< ... d 60033 14
jr z,rightedge 60034 28 12 ... e 60051 1C
jr seekright 60052 18 E9
jr nz,nextrun 60057 20 CC
A Neat Redefine Keys RoutinePreviously, I’ve only shared this routine with a couple of people via PM, but I’ve now decided to make it public. I optimized it for size, so it uses…
... 32 ;is it SPACE?
jr nz,enter_key ;if not, check if ... 13 ;is it ENTER?
jr nz,ss_key ;if not, check if ... ;is it SYMBOL SHIFT?
jr nz,cs_key ;if not, check if ... ;is it CAPS SHIFT?
jr nz,as_is_key ;if not, then print ...Other than using attributes what other ways to detect collisions, when using char based movement?So I'm slowly working out the bits and pieces to write a game completely in assembly. I've been using attributes when writing in BASIC to detect whet…
No-tearing (“vsync”) Full Screen FadeSeeing as most screen fades exhibit visible tearing, I wrote my own routine which does away with that problem. Simple, effective, short, and fully re…
... timings of different machines
jr nz,1$ ;before we start drawing ... ,a ;copy into C
jr z,f1 ;leave it alone ... /> and $38 ;isolate PAPER
jr z,f2 ;leave it alone ... end of attr area?
jr nz,fade1 ;repeat if not
